DESCRIPTION:(adapted from applicant?s abstract) This research project examines learning and plasticity in the hippocampus of food-storing birds. The first three experiments address the role of the hippocampus in spatial memory processing, through the use of reversible inactivation or injection of receptor antagonists. The fourth experiment examines factors that may induce seasonal neurogenesis by manipulating experience and hormone levels. This research will contribute to our understanding of the neural basis of learned behaviors in the following ways; first, by studying a natural behavior, we can increase the generality and validity of our current theories on the neural basis of learning and memory. Second, by studying a system with remarkable adult neural plasticity, we may better understand the link between plasticity in the nervous sytem and changes in cognitive function. This in turn may be relevant to therapeutic strategies involving brain repair, by revealing the mechanisms through which adult generated neurons become functionally integrated into the nervous system.